1.Assuming SX50, that's all there is, assuming you are talking about the console.
2.Look at "Flexible Night Service" in the console guide. Someone has redirected the calls to.... ?
(This often turns out to be a vacant room so the night clerk can 'nap'.)
3.Lock is normally caused by the phone being off-hook for an extended time. Usually, the problem is cleared by hanging up the phone. Then wait 5 minutes and try to make a call from the room. If that is OK, then try calling the room from the console.

All these answers are based on SX50. 200D/LIGHT/ML-EL/IPC Have similar, but different, answers. We need to know the system model in future posts.

When I was young, I was Liberal. As I aged and wised up, I became Conservative. Now that I'm old, I have settled on Curmudgeon.